Dishwashing machine



Oct 30, 1951 s. c. G. sANDBERG 2,573,067

DISHWASHING MACHINE Filed June 27, 194'? Patented Oct. 30, 1951 UNITEDSTATES PATENT *oEFIcE Application June 27, 1947, Serial No. 757,451

In Sweden May 31, 1945 The present invention relates t'o improvements indish washing machines.

It is vone of the objects of the present invention to provide a dishWashing machine having improved characteristics so far as the waterspraying impeller is concerned.

A further object of the invention is to provide a dish washing machinehaving an impeller so constituted as to throw upwardly against thedishes or other objects therein a powerful spray of a mixture of air andwater orvother liquid.

A still further object of the invention is to provide a dish washingmachine provided with automatic means for controlling the water leveltherein and means for throwing the water so controlled as to its 'level'forcibly against the dishes in the'machine. f

Further objects of the invention will appear from the description anddrawing led concurrently herewith in which l Figure 1 is an elevationalview partly in cross section; T

` Fig. 2 is a perspective view on an enlarged scale of the specialimpeller used in the machine; and

Fig. 3 is a cross section along the line 3--3 of Fig. 2.

The dish washing4 machine of the present invention comprises an uprightcontainer I supportedV on a suitable supporting structure 2 and providedwith an opening 3 which may be covered by means of a cover 4 which isprovided preferably with a transparent glass plate 4'.- Housed withinthe containerl are a plurality of baskets, for example a basket 5,intended, for instance, for the reception of dishes,` a centrallylocated somewhat taller basket 6 intended for the reception of knives,forks, spoons, etc., and anV upper basket 1 which is intended for cups,glassesand the like. The lower basket rests on a suitable support I5'having dependinglegs resting on,` the bottom of the container.Intermediate between the lower portion of the machine and the basket 5is a transversely extending upwardly arched screen 8. The lower portionof the container is provided with a discharge pipe 9 which is located inthe bottom of the vessel and which is covered by means of the screen II, the said pipe also being provided with a, discharge valve I0.

In order to automatically maintain a definite Water level in the lowerpart of the container I, there is provided a screened discharge openingI2 which is connected with a bent pipe I3 which leads to the dischargeline 9 at a point beyond the valve I0 so that irrespective of theclosing of the valve I0 only as much water can be placed 2 Claims. (Cl.299-63) in the bottom of the vessel I as will correspond to the overiiowlevel provided by the screened opening I2. Passing through a suitablebearing I4 provided in the central bottom portion of the container is asuitable vertical axle I5 to which there is attached the hub of animpeller, the blades of which are broadly designated by the referencenumeral I6. The axle I5 is connected preferably by means of a resilientcoupling I'I, which may be made of rubber or the like, to the driveshaft I8 of a suitable prime mover I9 which may take the form of anelectric motor. This motor is, moreover, secured by means of the ring 20to transverse supports which are a part of the supporting structure 2 ofthe machine. The impeller is moreover provided with a hub 25 which issecured by meansv of suitable fastening means 2|.

The propeller blades 212 are, in accordance with the present invention,made with spaced double walls 23 and 24, the ends of which are securedto or made integral with the hub 25 of the impeller, the two walls 23and 24 being secured together or made integral along a portion of theirouter edges 26, thus providing between the two walls a channel orpassageway 2l (see particularly Fig. 3), the cross section of thischannel being more or less crescent shaped and also graduallydiminishing from the hub outward to the outer edge'of the impeller.There will thus also remain a lateral or side opening 35 leading to thepassageway 21.

As can best be seen by examining `the part of the impeller which is atthe upper portion of Fig. 2, the foremost wall 23 doesv not extend quiteso far along the hub 25 as does the rear wall i24, and moreover, it willbe seen that there is an intake 28 leading to the channel 21 and also anoutlet 29 at the upper or trailing edge of the impeller. The twoadjacent edges 39 and 3| constitute what will hereinafter be referred toas the leading edge of the impeller blade.

Accordingly it will be seen that if the impeller is rotated in acounterclockwise direction as shown by the arrow in Fig. 2, any watercontained in the lower portion of the dish washing machine, which waterwill have a level no higher than that corresponding to the overflow pipeI2, will be picked up by the lowermost leading edge 3l, and theuppermost leading edge 3U, so that the Water will be caused to pass intothe channel 21 and, as a result of the centrifugal forces developed,will be caused to pass more or less along the lines of the dotted arrowsshown in Fig. 2, to be discharged with considerable violence fromtherefor.

the upper and trailing edges of the impeller. It will of course also beevident that such water as is picked up by the edge 30 will have atendency to be thrown outwardly and upwardly toward the inner Walls ofthe vessel I. However, a considerable portion of the water will travelalmost straight upwardly, that is to say, parallel to the axis ofrotation of the -hub 25 so that the water will traverse the centerportion of the `basket yii and also baskets and 1.

As the water is thrown upwardly and no further water is introduced intothe machine, it will be evident that the water level in the lowerportion of the vessel will be lowered -by reason of the amount of waterwhich is now in process of impinging upon the dishes whichare beingwashed, with the result that openings 35 at the outer edges of theblades are partly above the water level so that air will be drawn intothe channel 21 and will hence traverse said channel together nl issomewhat narrower at the top than 'at 'the bottom, and also narrower atthe trailing edge than at the 'leading edge, the air -will vfirst becompressed and then, yas it escapes from 'the trailing edge v2li, willagain expand, thereby causing the water to "be discharged in the 'formof numerousair bubbles. The 'total effect is a v ery violent general.upwardly directed spray of air and water which serves to wash thedishes placed in the apparatus.

The action of 'the double-walled impeller v'is .particularlyeffective'in that it provides not only an upwardly directed spraydeveloped primarily 1in the channel ifljbut alsoa certain amount of-ableindent rlillgnfiaybe provided as shown at the topof Figfl, although.of course a handle or-a'ny other suitable lifting means V.can besubstituted The coverfmaymerely rest on the device `if -it -is circular,or may 'be lhinged if 'the cross sectionofthe macline'is rectangular.For most-purposes, however, :the vessel l'is tobe considered -as beingcylindrical, kbut the n.invention 'is by no means limited to such.a-construction.

The dish washing-machine of the-present infvention maybe constructed ofany suitablefmaterial -such as aluminum, .stainless steel, Monel metal,copperor enameled metal, or even plastic 4material-,z'provided only`that the` essential features Yherein illustrated 4for purposes yofexample are -material, but is `preferably made of v'bronze vor brass, orother material which is not subject to rusting or ready deterioration.The impeller may therefore be either cast or the parts may be attachedby welding, while the portion 26 where the two walls 23 and 24 meet, mayeither be integral or may be produced by welding, swaging or brazing.

Obvious modications such as lie within the skill of the trained mechanicare to be construed as within the scope and purview of the presentinvention, for which applicant claims:

1. An impeller for dish washing machines and the like comprising a hub,at least two impeller blades Ysecured -thereto and radiating therefrom,saidblades consisting of two components of substantially vvthe sameshape spaced slightly apart but secured to each other along a portion oftheir outer edges, thereby leaving a channel therebetween, the leadingedges of said components being ilared and with the most advanced edgebeing longer than 'the other whereby liquid -will be scooped up bysaidle'a'dingedgesupon rotation o'f 'the 'hu'b and the 'liquid'caused topass rapidly through said channel and ito be 'dischargedyio- `lently'from the 'tra'iling *edges of 'the blades Lin the lgeneral direction ofthe axis vof urotation fof said hub.

2. In Va dish washing machine having *a housing, means 'for holding'articlesto "be Washed,

and -meansfor agitating and spraying'liquid 'contained Vin lthe (lowerportion of saidhousing 'in an upward direction, 'the i'mprovement whichcomprises a vertical 'shaft'and 'a 'hub mounted thereon, said hb.carrying "radially spaced laminar impellerbladesjthe 4outer edges o'fwhich are secured to each otheralong a portionofsaid edges so as .to.provide .achannel therebetween, lwhereby liquid will be scooped'upbysaidblades with their leading edges fand caused to 'iiow violentlyvthrough .the .same and 'be .discharged upwardly from the trailing edgesof saidblades, while air lwill be drawn in through the open portions of-theouter edges.

{STIG 'CTGNNY' GEGRG SANDBERG.

REFERENCES CITED The following references are '.'of 'record 'in Lthev'file of 'thi'spantent UNITED .STATES PATENTS Number 'Name :Date

262,681 Maringer .r-Aug. 15, 17882 l'l,409',571 'Putman Mantle, 1922v1,526,958 Blakeslee :'Feb."-.1f7, 1925 l1-,68'6j4`5'6 Kohler "Oct. 2,T1928 v"818,029 :Anstiss Aug 11111931 51,884,180 :Pauly 'Oct. 25, .1932112944,322 ilohnson Jan. 323, 11934 2,000;720

Snyder :et uil. May' 7 .-1935

